diff options
Diffstat (limited to 'c/src/exec/score/cpu/m68k/cpu.h')
| -rw-r--r-- | c/src/exec/score/cpu/m68k/cpu.h | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/c/src/exec/score/cpu/m68k/cpu.h b/c/src/exec/score/cpu/m68k/cpu.h index bc83bf3138..46500e90f1 100644 --- a/c/src/exec/score/cpu/m68k/cpu.h +++ b/c/src/exec/score/cpu/m68k/cpu.h @@ -52,12 +52,22 @@ extern "C" { /* * Some family members have no FP, some have an FPU such as the * MC68881/MC68882 for the MC68020, others have it built in (MC68030, 040). + * + * NOTE: If on a CPU without hardware FP, then one can use software + * emulation. The gcc software FP emulation code has data which + * must be contexted switched on a per task basis. */ #if ( M68K_HAS_FPU == 1 ) #define CPU_HARDWARE_FP TRUE +#define CPU_SOFTWARE_FP FALSE #else #define CPU_HARDWARE_FP FALSE +#if defined(__GCC__) +#define CPU_SOFTWARE_FP TRUE +#else +#define CPU_SOFTWARE_FP FALSE +#endif #endif /* @@ -108,6 +118,38 @@ typedef struct { } Context_Control; /* + * Floating point context ares + */ + +#if (CPU_SOFTWARE_FP == TRUE) + +/* + * This is the same as gcc's view of the software FP condition code + * register _fpCCR. The implementation of the emulation code is + * in the gcc-VERSION/config/m68k directory. This structure is + * correct as of gcc 2.7.2.2. + */ + +typedef struct { + unsigned16 _exception_bits; + unsigned16 _trap_enable_bits; + unsigned16 _sticky_bits; + unsigned16 _rounding_mode; + unsigned16 _format; + unsigned16 _last_operation; + union { + float sf; + double df; + } _operand1; + union { + float sf; + double df; + } _operand2; +} Context_Control_fp; + +#else + +/* * FP context save area for the M68881/M68882 numeric coprocessors. */ @@ -117,6 +159,7 @@ typedef struct { /* 12 bytes for FMOVEM CREGS */ /* 4 bytes for non-null flag */ } Context_Control_fp; +#endif /* * The following structure defines the set of information saved @@ -291,6 +334,34 @@ unsigned32 _CPU_ISR_Get_level( void ); : "0" ((_the_context)->sr), "1" ((_the_context)->a7_msp) ); \ } +/* + * Floating Point Context Area Support routines + */ + +#if (CPU_SOFTWARE_FP == TRUE) + +/* + * This software FP implementation is only for GCC. + */ + +#define _CPU_Context_Fp_start( _base, _offset ) \ + ((void *) _Addresses_Add_offset( (_base), (_offset) ) ) + + +#define _CPU_Context_Initialize_fp( _fp_area ) \ + { \ + Context_Control_fp *_fp; \ + _fp = *(Context_Control_fp **)_fp_area; \ + _fp->_exception_bits = 0; \ + _fp->_trap_enable_bits = 0; \ + _fp->_sticky_bits = 0; \ + _fp->_rounding_mode = 0; /* ROUND_TO_NEAREST */ \ + _fp->_format = 0; /* NIL */ \ + _fp->_last_operation = 0; /* NOOP */ \ + _fp->_operand1.df = 0; \ + _fp->_operand2.df = 0; \ + } +#else #define _CPU_Context_Fp_start( _base, _offset ) \ ((void *) \ _Addresses_Add_offset( \ @@ -305,6 +376,7 @@ unsigned32 _CPU_ISR_Get_level( void ); *(--(_fp_context)) = 0; \ *(_fp_area) = (unsigned8 *)(_fp_context); \ } +#endif /* end of Context handler macros */ |